1. Field of the Invention
The present invention relates generally to an arrangement in a cutting machine comprising cutting means disposed in a housing for comminuting material to be chopped.
In accordance with the embodiment of the invention to be described and illustrated herein and which is the one preferred at the moment, the cutting machine is a straw chopper for use in connection with a harvester combine, and wherein the cutting means comprises a chopper rotor having rotating knives and being rotatably mounted inside the housing, and counter-knives stationarily mounted inside the housing for cooperation with the rotating knives In accordance with the application referred to herein the material to be chopped consists of ordinary, dry straw, typically from wheat, barley, rye and oat, but the material may also originate from maize, sunflower or other plants comprising rather large and stiff plant parts.
2. Discussion of the Prior Act
Modern harvester combines are becoming larger and larger and their cutting tables wider and wider, considerably wider than the width of the combine proper. The cutting machine/rotary chopper connected to the combine has a width aproximately equal to that of the combine proper and it is designed to comminute or chop the material/straw after the threshing operation and to spread the material across an area which essentially corresponds to the width of the table, whereupon the material is mulched down into the soil. The spreading width of the chopper has reached its ultimate limit, which in the latest models of harvester combines having very large tables (close to 9 m) means that the material cannot be spread all the way to the side edges of the threshed string on the field being harvested. The result is an uneven distribution of the comminuted material across the threshed string (equalling the width of the table) with consequential differing cultivation conditions involving poor growth in the areas adjacent.